This guide was purchased to help me in a project comparing cost of polyethylene pipe, PVC sch. 80 pipe, stainless O.D. tubing joined with compression fittings or welded, stainless sch 10 pipe joined by welding or Press-fit couplings (Victaulic). These needs are quite specific and I was looking for the maximum sizes in each material/method. The guide was helpful to an extent - better than any other guide on the market - but still somewhat limited. For example, PVC fittings only go to "8, stainless steel to 12", and nothing on stainless compression or Pressfit. I would say that its excellent for residential, commercial, and "light" industrial. If one"s needs were in those areas, the guide would be much more helpful. The deducts for omitting hangers and supports were helpful for my project. For my project, it would have been helpful for Pressfit and compression fitting info up to 2 inch, PVC sch 80 fittings to at least 12 inch (or larger) and stainless to 24 inch. HDPE info was...